TI TSC2102

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SLAS379A− APRIL 2003 − REVISED JUNE 2004
FEATURES
D 4-Wire Touch Screen Interface
D Integrated Touch Screen Processor With
D
D
D
D
D
D
D
D
Fully Automated Modes of Operation
Programmable Converter Resolution, Speed,
and Averaging
Programmable Autonomous Timing Control
Direct Battery Measurement
On-Chip Temperature Measurement
Stereo Audio Playback Up to 48 ksps
97-dB Stereo Audio Playback
Integrated PLL for Audio Clock Generation
Programmable Digital Audio Effects
Processing
Stereo Headphone Amplifier
SPI Serial Interface
D
D
D Glueless Interface With OMAP and Xscale
Processors
D Full Power-Down Control
D Low Power: 11-mW Stereo Audio Playback
D 32-Pin TSSOP Package
APPLICATIONS
D Personal Digital Assistants
D Smart Cellular Phones
D MP3 Players
DESCRIPTION
The TSC2102 is a highly integrated combination resistive
touch screen controller with on-chip processor and audio
DAC. The touch screen portion of the TSC2102 contains
a 12-bit 4-wire resistive touch screen converter complete
with drivers, and interfaces to the host controller through
a standard SPI serial interface. The on-chip processor
provides extensive features specifically designed to
reduce host processor and bus overhead, with capabilities
that include fully automated operating modes,
programmable conversion resolution up to 12 bits,
programmable sampling rates up to 125 kHz,
programmable conversion averaging, and programmable
on-chip timing generation.
The TSC2102 also features a high-performance audio
DAC with 16, 20, 24, or 32-bit stereo playback functionality
at up to 48 ksps. The stereo output drivers on the TSC2102
can be programmed for headphone drive or line-level
drive, and support capless as well as ac-coupled output
configurations. The digital audio data format is
programmable to work with popular audio standard
protocols (I2S, DSP, left/right justified) in master or slave
mode, and also includes an on-chip PLL for flexible clock
generation capability.
The TSC2102 offers two battery measurement inputs
capable of reading battery voltages up to 6 V, while
operating at only 2.7 V. It also has an on-chip temperature
sensor capable of reading 0.3°C resolution. The TSC2102
is available in a 32-lead TSSOP.
US Patent No. 624639
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments
semiconductor products and disclaimers thereto appears at the end of this data sheet.
SPI is a trademark of Motorola.
OMAP is a trademark of Texas Instruments.
Xscale is a trademark of Intel.
!"# $"%&! '#( '"!
! $#!! $# )# # #* "# '' +,(
'"! $!#- '# #!#&, !&"'# #- && $##(
Copyright  2003−2004, Texas Instruments Incorporated
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate
precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to
damage because very small parametric changes could cause the device not to meet its published specifications.
PACKAGE/ORDERING INFORMATION
PRODUCT
PACKAGE
PACKAGE DESIGNATOR
OPERATING
TEMPERATURE RANGE
TSC2102IDA
TSSOP-32
360
−40°C to +85°C
ORDERING NUMBER
TRANSPORT MEDIA
TSC2102IDA
Rails
TSC2102IDAR
Tape and Reel
PIN ASSIGNMENTS
(TOP VIEW)
TSSOP
DIN
NC
BCLK
DVDD
DVSS
IOVDD
MCLK
SCLK
MISO
MOSI
SS
PINTDAV
NC
NC
AUX
VBAT2
1
32
2
31
3
30
4
29
5
28
6
27
7
26
8
25
9
24
10
23
11
22
12
21
13
20
14
19
15
18
16
17
PWD
LRCK
RESET
HPR
DRVDD
VGND
DRVSS
HPL
AVDD
X+
Y+
X−
Y−
AVSS
VREF
VBAT1
Terminal Functions
2
PIN
NAME
INPUT/
OUTPUT
1
DIN
I
2
NC
3
BCLK
I/O
4
DVDD
5
DVSS
6
DESCRIPTION
PIN
NAME
INPUT/
OUTPUT
DESCRIPTION
Digital audio data input
17
VBAT1
I
No connection
18
VREF
I/O
Audio bit clock to be consistent
with pin 31 word-clock
19
AVSS
I
I
Digital core supply
20
Y−
I/O
Y− position input and driver
I
Digital core and IO ground
21
X−
I/O
X− position input and driver
IOVDD
I
IO supply
22
Y+
I/O
Y+ position input and driver
7
MCLK
I
Master clock
23
X+
I/O
X+ position input and driver
8
SCLK
I
SPI serial clock input
24
AVDD
I
Analog power supply
9
MISO
O
SPI serial data output
25
HPL
O
Left channel audio output
10
MOSI
I
SPI serial data input
26
DRVSS
I
Speaker ground
Battery monitor input 1
Reference voltage
Analog ground
11
SS
I
SPI slave select input
27
VGND
O
Virtual ground for audio output
12
PINTDAV
O
Pen interrupt/data available output
28
DRVDD
I
Speaker and PLL supply
13
NC
No connection
29
HPR
O
Right channel audio output
14
NC
No connection
30
RESET
I
Device reset
15
AUX
I
Auxiliary input
31
LRCK
I/O
Audio DAC word-clock
16
VBAT2
I
Battery monitor input 2
32
PWD
I
Hardware power down
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ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range unless otherwise noted(1)
UNITS
AVDD to AVSS
−0.3 V to 3.9 V
DRVDD to DRVSS
−0.3 V to 3.9 V
IOVDD to DVSS
−0.3 V to 3.9 V
DVDD to DVSS
−0.3 V to 2.5 V
Digital input voltage to GND
−0.3 V to IOVDD + 0.3 V
Operating temperature range
−40°C to 85°C
Storage temperature range
−65°C to 105°C
Junction temperature (TJ Max)
105°C
Power dissipation
TSSOP package
Lead temperature
(TJ Max − TA)/θJA
60°C/W
θJA Thermal impedance
Soldering vapor phase (60 sec)
215°C
Infrared (15 sec)
220°C
(1) Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
At +25°C, AVDD,DRVDD,IOVDD = 3.3 V, DVDD = 1.8 V, Int. Vref = 2.5 V, Fs (Audio) = 48 kHz, unless otherwise noted
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
TOUCH SCREEN
AUXILIARY ANALOG INPUT
Input voltage range
Input capacitance
0
AUX input selected as input by touch-screen
ADC
Input leakage current
+VREF
V
25
pF
±1
µA
BATTERY MONITOR INPUTS
Input voltage range
Input leakage current
0.5
6.0
±1
Battery conversion not selected
V
µA
TOUCH SCREEN A/D CONVERTER
Resolution
Programmable: 8-, 10-,12-bits
No missing codes
12-bit resolution
12
11
Bits
Bits
Integral nonlinearity
−5
5
LSB
Offset error
−6
6
LSB
−6
6
LSB
Gain error
Gain error is calculated with the effect of
internal reference variation removed.
Noise
µVrms
50
STEREO AUDIO CODEC
DAC INTERPOLATION FILTER
Pass band
20
Transition band
Stop band
Stop band attenuation
Filter group delay
De−emphasis error
0.45Fs
±0.06
Pass band ripple
Hz
dB
0.45Fs
0.5501Fs
Hz
0.5501Fs
7.455Fs
Hz
65
dB
21/Fs
Sec
±0.1
dB
3
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
ELECTRICAL CHARACTERISTICS (continued)
At +25°C, AVDD,DRVDD,IOVDD = 3.3 V, DVDD = 1.8 V, Int. Vref = 2.5 V, Fs (Audio) = 48 kHz, unless otherwise noted (continued)
PARAMETER
DAC LINE OUTPUT
(16−W driver bypassed)
TEST CONDITIONS
MIN
TYP
0.707
Output common mode
Vrms
1.35
SNR
Measured as idle channel noise, A-weighted
THD
0-dB FS input, 0-dB gain
PSRR
1 kHz, 100mVpp on AVDD(1)
DAC HEADPHONE OUTPUT
Load = 16 Ω, 10 pF
SNR
Measured as idle channel noise, A-weighted
THD
−1 dBFS input, 0-dB gain
PSRR
1 kHz, 100 mVpp on AVDD(1)
85
85
dBA
−97
dB
55
dB
96
dBA
−55
50
Per channel
Digital volume control
V
97
−65
Mute attenuation
Between HPR and HPL
dB
dB
90
dB
25
mW
−63.5
Digital volume control step size
Channel separation
UNITS
1020-Hz sine wave input, Fs = 48 ksps,
Load = 10 kΩ, 10 pF
Full scale output voltage (0 dB)
Maximum output power
MAX
0
dB
0.5
dB
90
dB
VOLTAGE REFERENCE
Voltage range
VREF output programmed as 2.5 V
2.3
2.5
2.7
VREF output programmed as 1.25 V
1.15
1.25
1.35
Voltage range
External reference
Reference drift
Internal VREF = 2.5 V
Current drain
Extra current drawn when the internal
reference is turned on.
1.2
2.55
V
V
50
ppm/°C
500
µA
DIGITAL INPUT / OUTPUT
Internal clock frequency
8
Logic family
Logic level:
CMOS
VIH
VIL
IIH = +5 µA
IIL = +5 µA
0.7xIOVDD
VOH
VOL
IOH = 2 TTL loads
IOL = 2 TTL loads
0.8xIOVDD
Capacitive load
4
MHz
V
−0.3
0.3xIOVDD
V
V
0.1xIOVDD
10
V
pF
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
ELECTRICAL CHARACTERISTICS (continued)
At +25°C, AVDD,DRVDD,IOVDD = 3.3 V, DVDD = 1.8 V, Int. Vref = 2.5 V, Fs (Audio) = 48 kHz, unless otherwise noted (continued)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
POWER SUPPLY REQUIREMENTS
Power supply voltage
AVDD
2.7
3.6
DRVDD
2.7
3.6
V
IOVDD
2.7
3.6
V
1.525
1.95
V
DVDD
Touch-screen ADC quiescent current
Analog supply current – Audio play back only
Digital supply current – Audio play back only
IAVDD, host controlled AUX conversion at
10 ksps with external reference
45
IDVDD, host controlled AUX conversion at
10 ksps
65
IAVDD + IDRVDD, headphone driver
bypassed, VGND off, PLL off, no signal
2.1
IAVDD + IDRVDD, headphone driver and
VGND on, PLL off, no signal
7.1
48 ksps, PLL off, no signal
2.2
IDRVDD
PLL current
IDVDD
Hardware power down. All digital inputs at 0 V
or IOVDD.
Total current
V
µA
A
mA
mA
1
0.8
5
mA
µA
(1) DAC PSRR measurement is calculated as:
ǒ
PSRR + 20 log 10
Ǔ
VSIG sup
V
HPRńL
where VSIGsup is the ac signal applied on AVDD, which is 100 mVPP at 1 kHz, and VHPR/L is the peak-to-peak ac signal seen on HPR and HPL
outputs.
5
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
FUNCTIONAL BLOCK DIAGRAM
DRVDD
DRVSS
AVDD
AVSS
DVDD
DVSS
IOVDD
PLL
MCLK
Headphone
Driver
S-D
DAC
HPR
Volume
Control
0 to −63.5 dB
(0.5 dB Steps)
HPL
Headphone
Driver
S-D
DAC
Volume
Control
Digital
Audio
Processing
And
Serial
Interface
PWD
LRCK
DIN
BCLK
DAC CM
VGND
RESET
AUX
X+
Y+
X−
Y−
Touch
Panel
Drivers
VBAT1
Battery
Monitor
VBAT2
Battery
Monitor
Touch
Screen
Processing
And
Control
SPI
Interface
SAR
ADC
6
SS
MOSI
MISO
PINTDAV
Temperature
Measurement
VREF
SCLK
Internal 2.5/
1.25-V
Reference
OSC
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
SPI TIMING DIAGRAM
SS
tLag
tsck
tLead
tf
twsck
SCLK
t
td
tr
twsck
tv
MISO
t
MSB OUT
ta
t su
MOSI
tdis
oh
BIT 6 . . . 1
LSB OUT
t hi
BIT 6 . . . 1
MSB IN
LSB IN
TYPICAL TIMING REQUIREMENTS
All specifications at 25°C, IOVDD = 3.3 V, DVDD = 1.8 V(1)
PARAMETER
MIN
MAX
UNITS
twsck
tLead
SCLK pulse width
18
ns
Enable lead time
15
ns
tLag
ttd
Enable lag time
15
ns
Sequential transfer delay
15
ta
tdis
Slave MISO access time
15
ns
Slave MISO disable time
15
ns
tsu
thi
MOSI data setup time
6
ns
MOSI data hold time
6
ns
tho
tv
MISO data hold time
4
MISO data valid time
tr
Rise time
tf
Fall time
(1) These parameters are based on characterization and are not tested in production.
ns
ns
13
ns
4
ns
4
ns
7
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AUDIO INTERFACE TIMING DIAGRAMS
LRCK
td(WS)
BCLK
ts (DI)
th (DI)
DIN
Figure 1. I2S/LJF/RJF Timing in Master Mode
TYPICAL TIMING REQUIREMENTS
All specifications at 25°C, IOVDD = 3.3 V, DVDD = 1.8 V(1)
PARAMETER
MIN
MAX
15
UNITS
td (WS)
ts(DI)
LRCK delay
DIN setup
6
ns
th(DI)
tr
DIN hold
6
ns
Rise time
tf
Fall time
(1) These parameters are based on characterization and are not tested in production.
ns
6
ns
6
ns
LRCK
td(WS)
td(WS)
BCLK
ts (DI)
th (DI)
DIN
Figure 2. DSP Timing in Master Mode
TYPICAL TIMING REQUIREMENTS
All specifications at 25°C, IOVDD = 3.3 V, DVDD = 1.8 V(1)
PARAMETER
MIN
td (WS)
ts(DI)
LRCK delay
DIN setup
6
th(DI)
tr
DIN hold
6
Rise time
tf
Fall time
(1) These parameters are based on characterization and are not tested in production.
8
MAX
15
UNITS
ns
ns
ns
6
ns
6
ns
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
LRCK
th(WS)
tL(BCLK)
ts(WS)
tH(BCLK)
BCLK
tP(BCLK)
ts (DI)
th (DI)
DIN
Figure 3. I2S/LJF/RJF Timing in Slave Mode
TYPICAL TIMING REQUIREMENTS
All specifications at 25°C, IOVDD = 3.3 V, DVDD = 1.8 V(1)
PARAMETER
MIN
MAX
UNITS
tH (BCLK)
tL (BCLK)
BCLK high period
35
ns
BCLK low period
35
ns
tP (BCLK)
ts(WS)
BCLK period
85
ns
LRCK setup
6
ns
th(WS)
ts(DI)
LRCK hold
6
ns
DIN setup
6
ns
th(DI)
tr
DIN hold
6
Rise time
tf
Fall time
(1) These parameters are based on characterization and are not tested in production.
ns
4
ns
4
ns
LRCK
th(WS)
BCLK
ts(WS)
th(WS)
ts(WS)
tL(BCLK)
tH(BCLK)
tP(BCLK)
ts (DI)
th (DI)
DIN
Figure 4. DSP Timing in Slave Mode
TYPICAL TIMING REQUIREMENTS
All specifications at 25°C, IOVDD = 3.3 V, DVDD = 1.8 V(1)
PARAMETER
MIN
MAX
UNITS
tH (BCLK)
tL (BCLK)
BCLK high period
35
ns
BCLK low period
35
ns
tP (BCLK)
ts(WS)
BCLK period
85
ns
LRCK setup
6
ns
th(WS)
ts(DI)
LRCK hold
6
ns
DIN setup
6
ns
th(DI)
tr
DIN hold
6
ns
Rise time
tf
Fall time
(1) These parameters are based on characterization and are not tested in production.
4
ns
4
ns
9
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TYPICAL CHARACTERISTICS
1.5
1
LSB
0.5
0
−0.5
−1
−1.5
0
500
1000
1500
2000
2500
3000
3500
4000
CODE
Figure 5. SAR INL (TA = 255C, Internal Ref = 2.5 V, 12 bit, AVDD = 3.3 V)
1
LSB
0.5
0
s
−0.5
−1
0
500
1000
1500
2000
2500
3000
3500
4000
CODE
Figure 6. SAR DNL (TA = 255C, Internal Ref = 2.5 V, AVDD = 3.3 V)
10
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
1.8
1.6
Power − mW
1.4
1.2
1
0.8
0.6
0.4
0.2
0
0
20
40
60
80
Sampling Rate (ksps)
Figure 7. Touch Screen Power Consumption With Speed (TA = 255C, External Ref, Host Controlled AUX
Conversion, AVDD = 3.3 V)
0
−20
−40
dB
−60
−80
−100
−120
−140
−160
0
5000
10000
15000
20000
Hz
Figure 8. DAC FFT Plot (TA = 255C, 48 ksps, 0 dB, 1 kHz Input, AVDD = 3.3 V, RL = 10 kW)
11
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OVERVIEW
The TSC2102 is a highly integrated touch screen controller with stereo audio DAC for portable computing, communication,
and entertainment applications. A register-based architecture eases integration with microprocessor-based systems
through a standard SPI bus. All peripheral functions are controlled through the registers and onboard state machines.
The TSC2102 consists of the following blocks (refer to the block diagram):
D
D
D
D
D
Touch Screen Interface
Battery Monitors
Auxiliary Input
Temperature Monitor
Audio DAC
Communication with the TSC2102 is via standard SPI serial interface. This interface requires that the slave select signal
be driven low to communicate with the TSC2102. Data is then shifted into or out of the TSC2102 under control of the host
microprocessor, which also provides the serial data clock. Control of the TSC2102 and its functions is accomplished by
writing to different registers in the TSC2102. A simple command protocol is used to address the 16-bit registers. Registers
control the operation of the A/D converter and audio DAC.
Control of the TSC2102 and its functions is accomplished by writing to different registers in the TSC2102. A simple
command protocol is used to address the 16−bit registers. Registers control the operation of the A/D converter and audio
DAC.
The TSC2102 audio serial interface is exclusively used by the stereo DAC and supports four audio interface modes (I2S,
DSP, right justified, and left justified) to receive digital audio data from the host processor.
A typical application of the TSC2102 is shown in Figure 9.
I2S Interface
Auxilary Input
Touch
Screen
AUX
X+
Y+
MCLK
Master Clock Input
LRCK
DAC Word Select
DIN
X−
BCLK
Y−
Audio
R1
R2
V1: Main Battery
V2: Secondary Battery
C1: 1 µF − 10 µF (Optional)
C2: 0.1 µF
R1,R2: 200−300 Ω
V2
C1
PINTDAV
Pen Interrupt Request to CPU
MISO
Serial Output to SPI Master
VBAT1
MOSI
Serial Input From SPI Master
VBAT2
SS
SPI Slave Select Input
MOSI
SPI Serial Clock Input
VREF
C2
SPI Interface
Figure 9. Typical Circuit Configuration
12
Serial Clock Input
TSC2102
HPR
VGND
HPL
V1
Serial Input From CPU/DSP
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OPERATION—TOUCH SCREEN
A resistive touch screen works by applying a voltage across a resistor network and measuring the change in resistance
at a given point on the matrix where a screen is touched by an input stylus, pen, or finger. The change in the resistance
ratio marks the location on the touch screen.
The TSC2102 supports the resistive 4-wire configurations (see Figure 9). The circuit determines location in two coordinate
pair dimensions, although a third dimension can be added for measuring pressure.
The 4-Wire Touch Screen Coordinate Pair Measurement
A 4-wire touch screen is constructed as shown in Figure 10. It consists of two transparent resistive layers separated by
insulating spacers.
Conductive Bar
Transparent Conductor (ITO)
Bottom Side
Y+
X+
Transparent Conductor (ITO)
Top Side
X−
Silver Ink
Y−
Insulating Material (Glass)
ITO= Indium Tin Oxide
Figure 10. 4-Wire Touch Screen Construction
The 4-wire touch screen panel works by applying a voltage across the vertical or horizontal resistive network. The ADC
converts the voltage measured at the point the panel is touched. A measurement of the Y position of the pointing device
is made by connecting the X+ input to an ADC, turning on the Y drivers, and digitizing the voltage seen at the X+ input.
The voltage measured is determined by the voltage divider developed at the point of touch. For this measurement, the
horizontal panel resistance in the X+ lead does not affect the conversion due to the high input impedance of the A/D
converter.
Voltage is then applied to the other axis, and the A/D converts the voltage representing the X position on the screen. This
provides the X and Y coordinates to the associated processor.
Measuring touch pressure (Z) can also be done with the TSC2102. To determine pen or finger touch, the pressure of the
touch needs to be determined. Generally, it is not necessary to have very high performance for this test; therefore, the 8-bit
resolution mode is recommended (however, calculations are shown with the 12-bit resolution mode). There are several
different ways of performing this measurement. The TSC2102 supports two methods. The first method requires knowing
the X-plate resistance, measurement of the X-Position, and two additional cross panel measurements (Z2 and Z1) of the
touch screen (see Figure 11). Using equation 1 calculates the touch resistance:
R
TOUCH
+R
X–plate
ǒ Ǔ
X–position Z 2
–1
4096
Z1
(1)
The second method requires knowing both the X-plate and Y-plate resistance, measurement of X-Position and Y-Position,
and Z1. Using equation 2 also calculates the touch resistance:
R
R
TOUCH
+
ǒ
Ǔ
X−position
X−plate
4096 * 1
4096
Z1
*R
Y−plate
ǒ1* Y−position
Ǔ
4096
(2)
13
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
Measure X-Position
Y+
X+
Measure Z1-Position
X+
X-Position
Z1-Position
i
Y−
X−
X+
Y+
Touch
Touch
Touch
X−
Y+
Y−
Z2-Position
X−
Y−
Measure Z2-Position
Figure 11. Pressure Measurement
When the touch panel is pressed or touched, and the drivers to the panel are turned on, the voltage across the touch panel
often overshoots and then slowly settles (decays) to a stable dc value. This is due to mechanical bouncing which is caused
by vibration of the top layer sheet of the touch panel when the panel is pressed. This settling time must be accounted for,
or else the converted value will be in error. Therefore, a delay must be introduced between the time the driver for a particular
measurement is turned on, and the time measurement is made.
In some applications, external capacitors may be required across the touch screen for filtering noise picked up by the touch
screen, i.e. noise generated by the LCD panel or back-light circuitry. The value of these capacitors provides a low-pass
filter to reduce the noise, but causes an additional settling time requirement when the panel is touched.
Several solutions to this problem are available in the TSC2102. A programmable delay time is available which sets the
delay between turning the drivers on and making a conversion. This is referred to as the panel voltage stabilization time,
and is used in some of the modes available in the TSC2102. In other modes, the TSC2102 can be commanded to turn on
the drivers only without performing a conversion. Time can then be allowed before the command is issued to perform a
conversion.
The TSC2102 touch screen interface can measure position (X, Y) and pressure (Z). Determination of these coordinates
is possible under three different modes of the A/D converter: (1) conversion controlled by the TSC2102, initiated by
detection of a touch; (2) conversion controlled by the TSC2102, initiated by the host responding to the PINTDAV signal;
or (3) conversion completely controlled by the host processor.
Touch-Screen A/D Converter
The analog inputs of the TSC2102 are shown in Figure 12. The analog inputs (X, Y, and Z touch panel coordinates, battery
voltage monitors, chip temperature and auxiliary input) are provided via a multiplexer to the successive approximation
register (SAR) analog-to-digital (A/D) converter. The A/D architecture is based on a capacitive redistribution architecture,
which inherently includes a sample/hold function.
A unique configuration of low on-resistance switches allows an unselected A/D input channel to provide power and an
accompanying pin to provide ground for driving the touch panel. By maintaining a differential input to the converter and a
differential reference input architecture, it is possible to negate errors caused by the driver switch on-resistances.
The A/D is controlled by an A/D converter control register. Several modes of operation are possible, depending upon the
bits set in the control register. Channel selection, scan operation, averaging, resolution, and conversion rate may all be
programmed through this register. These modes are outlined in the sections below for each type of analog input. The results
of conversions made are stored in the appropriate result register.
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PINTDAV
AVDD
VREF
DATAV
VREF
X+
X−
REFP
Y+
Y−
IN+
CONVERTER
IN−
REFM
VBAT2
VBAT1
AUX
AVSS
Figure 12. Simplified Diagram of the Analog Input Section
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Data Format
The TSC2102 output data is in unsigned binary format and can be read from the registers over the SPI interface.
Reference
The TSC2102 has an internal voltage reference that can be set to 1.25 V or 2.5 V through the reference control register.
The internal reference voltage must only be used in the single-ended mode for battery monitoring, temperature
measurement, and for utilizing the auxiliary inputs. Optimal touch screen performance is achieved when using a ratiometric
conversion, thus all touch screen measurements are done automatically in the ratiometric mode.
An external reference can also be applied to the VREF pin, and the internal reference can be turned off.
Variable Resolution
The TSC2102 provides three different resolutions for the ADC: 8-, 10- or 12-bits. Lower resolutions are often practical for
measurements such as touch pressure. Performing the conversions at lower resolution reduces the amount of time it takes
for the ADC to complete its conversion process, which lowers power consumption.
Conversion Clock and Conversion Time
The TSC2102 contains an internal 8-MHz clock, which is used to drive the state machines inside the device that perform
the many functions of the part. This clock is divided down to provide a clock to run the ADC. The division ratio for this clock
is set in the ADC control register. The ability to change the conversion clock rate allows the user to choose the optimal value
for resolution, speed, and power. If the 8-MHz clock is used directly, the ADC is limited to 8-bit resolution; using higher
resolutions at this speed does not result in accurate conversions. Using a 4-MHz conversion clock is suitable for 10-bit
resolution; 12-bit resolution requires that the conversion clock run at 1 or 2 MHz.
Regardless of the conversion clock speed, the internal clock runs nominally at 8 MHz. The conversion time of the TSC2102
is dependent upon several functions (see the section Touch Screen Conversion Initiated at Touch Detect in this data sheet).
While the conversion clock speed plays an important role in the time it takes for a conversion to complete, a certain number
of internal clock cycles is needed for proper sampling of the signal. Moreover, additional times, such as the panel voltage
stabilization time, can add significantly to the time it takes to perform a conversion. Conversion time can vary depending
upon the mode in which the TSC2102 is used. Throughout this data sheet, internal and conversion clock cycles are used
to describe the times that many functions take to execute. Considering the total system design, these times must be taken
into account by the user.
When the audio DAC is powered down, the touch screen A/D uses an internal oscillator for conversions. However, to save
power whenever the audio DAC is powered up, the internal oscillator is powered down and MCLK and BCLK are used to
clock the touch screen A/D.
Touch Detect/Data Available
The pen interrupt/data available (PINTDAV) output function is detailed in Figure 13. While in the power-down mode, the
Y– driver is ON and connected to AVSS and the X+ pin is connected through an on-chip pullup resistor to AVDD. In this
mode, the X+ pin is also connected to a digital buffer and mux to drive the PINTDAV output. When the panel is touched,
the X+ input is pulled to ground through the touch screen, and the pen−interrupt signal goes LOW due to the current path
through the panel to AVSS, initiating an interrupt to the processor. During the measurement cycles for X− and Y− position,
the X+ input is disconnected from the pen-interrupt circuit to prevent any leakage current from the pullup resistor flowing
through the touch screen, and thus causing conversion errors.
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DATAV
PINTDAV
50K
TEMP1
Y+
TEMP2
HIGH EXCEPT WHEN
TEMP1. TEMP2
ACTIVATED
TEMP DIODE
X+
Y−
ON
Y+ or X+ DRIVERS ON OR
TEMP1 , TEMP2
MEASUREMENTS
ACTIVATED
Figure 13. PINTDAV Functional Block Diagram
In modes where the TSC2102 needs to detect if the screen is still touched (for example, when doing a PINTDAV initiated
X, Y, and Z conversion), the TSC2102 must reset the drivers so that the 50-k resistor is connected. Because of the high
value of this pullup resistor, any capacitance on the touch screen inputs causes a long delay time, and may prevent the
detection from occurring correctly. To prevent this, the TSC2102 has a circuit that allows any screen capacitance to be
precharged, so that the pullup resistor does not have to be the only source for the charging current. The time allowed for
this precharge, as well as the time needed to sense if the screen is still touched, can be set in the configuration control
register D5−D0 of REG05H/Page1.
This does point out, however, the need to use the minimum capacitor values possible on the touch screen inputs. These
capacitors may be needed to reduce noise, but too large a value increases the needed precharge and sense times, as well
as panel voltage stabilization time.
The function of PINTDAV output is programmable and controlled by writing to the bits D15−D14 of REG 01H/Page1 as
described in the Table 1.
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Table 1. Programmable PINTDAV Functionality
D15−D14
PINTDAV FUNCTION
00
Acts as PEN interrupt (active low) only. When PEN touch is detected, PINTDAV goes low.(1)
01
Acts as data available (active low) only. The PINTDAV goes low as soon as one set of ADC conversions are completed for data
of X,Y, XYZ, battery input, or auxiliary input selected by D13−D10 in REG00H/Page1. The resulting ADC output is stored in the
appropriate registers. The PINTDAV remains low and goes high only after this complete set of registers selected by D13−D10
REG00H/Page1 is read out.
10
11
Acts as both PEN interrupt and data available. When PEN touch is detected, PINTDAV goes low and remains low. The PINTDAV
goes high only after one set of A/D conversions is completed for data of X,Y, XYZ, battery input, or auxiliary input selected by
D13−D10 in REG00H/Page1.
(1) See the section Conversion Time Calculation for the TSC2102 in this data sheet for timing diagrams and conversion time calculations.
Pen-touch detect circuit is disabled during hardware power down.
Touch Screen Measurements
The touch screen ADC can be controlled by the host processor or can be self−controlled to offload processing from the
host processor. Bit D15 of REG00H/Page1 sets the control mode of the TSC2102 touch screen ADC; and bit D12 of
REG01H/Page 1 can be read to check the control mode status.
Conversion Controlled by TSC2102 Initiated at Touch Detect
In this mode, the TSC2102 detects when the touch panel is touched and causes the PINTDAV line to go low. At the same
time, the TSC2102 starts up its internal clock. Assuming the part was configured to convert XY coordinates, it then turns
on the Y drivers, and after a programmed panel voltage stabilization time, powers up the ADC and converts the Y
coordinate. If averaging is selected, several conversions may take place; when data averaging is complete, the Y
coordinate result is stored in the Y register.
If the screen is still touched at this time, the X drivers are enabled, and the process repeats, but measuring instead the X
coordinate, storing the result in the X register.
If only X and Y coordinates are to be measured, then the conversion process is complete. The time it takes to complete
this process depends upon the selected resolution, internal conversion clock rate, averaging selected, panel voltage
stabilization time, and precharge and sense times.
If the pressure of the touch is also to be measured, the process continues in the same way, measuring the Z1 and Z2 values,
and placing them in the Z1 and Z2 registers. As before, this process time depends upon the settings described above.
See the section Conversion Time Calculation for the TSC2102 in this data sheet for timing diagrams and conversion time
calculations.
Conversion Controlled by TSC2102 Initiated by the Host
In this mode, the TSC2102 detects when the touch panel is touched and causes the pen-interrupt signal line to go low. The
host recognizes the interrupt request, and then writes to the ADC control register (D13−D10 REG00H/Page1) to select one
of the touch screen scan functions. The host can either choose to initiate one of the scan functions, in which case the
TSC2102 controls the driver turnons, and wait times (e.g. upon receiving the interrupt the host can initiate the continuous
scan function X−Y−Z1−Z2 after which the TSC2102 controls the rest of conversion). The host can also choose to control
each aspect of conversion by controlling the driver turnons and start of conversions. For example, upon receiving the
interrupt request, the host turns on the X drivers. After waiting for the settling time, the host then addresses the TSC2102
again, this time requesting an X coordinate conversion, and so on.
The main difference between this mode and the previous mode is that the host, not the TSC2102, controls the touch screen
scan functions.
See the section Conversion Time Calculation for the TSC2102 in this data sheet for timing diagrams and conversion time
calculations.
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Temperature Measurement
In some applications, such as battery recharging, a measurement of ambient temperature is required. The temperature
measurement technique used in the TSC2102 relies on the characteristics of a semiconductor junction operating at a fixed
current level. The forward diode voltage (VBE) has a well-defined characteristic versus temperature. The ambient
temperature can be predicted in applications by knowing the 25°C value of the VBE voltage and then monitoring the delta
of that voltage as the temperature changes.
The TSC2102 offers two modes of temperature measurement. The first mode requires a single reading to predict the
ambient temperature. A diode, as shown in Figure 14, is used during this measurement cycle. This voltage is typically 600
mV at 25°C with a 20-µA current through it. The absolute value of this diode voltage can vary a few millivolts. During the
final test of the end product, the diode voltage must be stored at a known temperature. Further calibration can be done to
calculate the precise temperature coefficient of the particular device. This method has a temperature resolution of
approximately 0.3 °C/LSB and accuracy of approximately 1°C.
X+
MUX
A/D
Converter
Temperature Select
TEMP0 TEMP1
Figure 14. Functional Block Diagram of Temperature Measurement Mode
The second mode uses a two-measurement (differential) method. This mode requires a second conversion with a current
82 times larger. The voltage difference between the first (TEMP1) and second (TEMP2) conversion, using 82 times the
bias current, is represented by:
kT
q
ln(N)
where:
N is the current ratio = 82
k = Boltzmann’s constant (1.38054 • 10−23 electrons volts/degrees Kelvin)
q = the electron charge (1.602189 • 10−19 °C)
T = the temperature in degrees Kelvin
This method provides resolution of approximately 1.5°C/LSB and accuracy of approximately 1°C. The equation for the
relation between differential code and temperature may vary slightly from device to device and can be calibrated at final
system test by the user.
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1400
ADC Code
1300
1200
1100
1000
900
800
−40
−20
0
20
40
60
80
Applied Temperature (deg. C)
Figure 15. Typical Plot for Single Measurement Method
240
230
Differential Code
220
210
200
190
180
170
160
150
−40
−20
0
20
40
60
80
Applied Temperature(deg. C)
Figure 16. Typical Plot for Differential Measurement Method
Temperature measurement can only be done in host controlled mode.
Battery Measurement
An added feature of the TSC2102 is the ability to monitor the battery voltage at the input side of a voltage regulator (LDO
or dc/dc converter), as shown in Figure 17. The battery voltage can vary from 0.5 V to 6 V while maintaining the analog
supply voltage to the TSC2102 in the range of 2.7 V to 3.6 V. The input voltage (VBAT1 or VBAT2) is divided down by a
factor of 6 so that a 6.0-V battery voltage is represented as 1.0 V to the ADC.It is advisable to add a series resistor of 200
to 300 Ω while connecting the battery terminal to the input pin (VBAT1 or VBAT2) as shown in Figure 17. Thus, the resultant
voltage converted by the ADC is given by:
V conv +
2.0K
12.0K ) R
V
battery
The internal resistors, which make up the resistor divider, are subject to ±20% device-to-device variation. In order to
minimize power consumption, the divider is only on during the sampling of the battery input.
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2.7 V to 3.6 V
LDO or DC-DC
Converter
Battery
0.5 to 6 V
+
−
VDD
R
VBAT
ADC
10 kΩ
2 kΩ
Figure 17. Battery Measurement Functional Block Diagram
Battery measurement can only be done in host controlled mode.
See the section Conversion Time Calculation for the TSC2102 and subsection Non Touch Measurement Operation in this
data sheet for timing diagrams and conversion time calculations.
Auxiliary Measurement
The auxiliary voltage input (AUX) can be measured in much the same way as the battery inputs. Applications might include
external temperature sensing, ambient light monitoring for controlling the back-light, or sensing the current drawn from the
battery. The auxiliary input can also be monitored continuously in scan mode.
Auxiliary measurement can only be done in host controlled mode.
See the section Conversion Time Calculation for the TSC2102 and subsection Non Touch Measurement Operation in this
data sheet for timing diagrams and conversion time calculations.
Port Scan
If making measurements of BAT1, BAT2, and AUX is desired on a periodic basis, the port scan mode can be used. This
mode causes the TSC2102 to sample and convert both battery inputs and the auxiliary input. At the end of this cycle, the
battery and auxiliary result registers contain the updated values. Thus, with one write to the TSC2102, the host can cause
three different measurements to be made.
Port scan can only be done in host−controlled mode.
See the section Conversion Time Calculation for the TSC2102 and subsection Port Scan Operation in this data sheet for
timing diagrams and conversion time calculations.
Hardware Reset
The device requires hardware reset (active low) after power up. A hardware reset pulse initializes all the internal registers
and counters.
Hardware Power Down
The device powers down all the internal circuitry to save power. All the register contents are maintained. Some counters
maintain their value. The hardware power-down circuit also disables the pen-touch detect circuit.
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OPERATION− STEREO AUDIO DAC
Audio Analog I/O
The TSC2102 has one stereo headphone output capable of driving a 16-Ω load at over 25 mW (with 3.3-V supply) (HPR,
HPL). The headphone driver can be bypassed by setting D12 in the control register 05H/Page2 to 0. The TSC2102 also
has a virtual ground (VGND) output, which can be optionally used to connect to the ground terminal of headphones to
eliminate the ac-coupling capacitor at the headphone output terminal. Bit D8 of control register 05H/Page2 controls the
VGND amplifier. A special circuit has been included in the TSC2102 to insert a short keyclick sound into the stereo audio
output, even when the audio DAC is powered down. The keyclick sound is used to provide feedback to the user when a
particular button is pressed or item is selected. The specific sound of the keyclick can be adjusted by varying several
register bits that control its frequency, duration, and amplitude.
Digital Audio Interface
Digital audio data samples can be transmitted between the TSC2102 and the CPU via the audio data serial port (BCLK,
LRCK, DIN) that can be configured to transfer digital data in four different formats: right justified, left justified, I2S, and DSP.
The four modes are MSB first and operate with variable word length of 16/20/24/32 bits. The TSC2102 audio data serial
port can operate in master or slave mode. The word-select signal (LRCK) and bit clock signal (BCLK) are output in master
mode and input in slave mode, and both can be turned off by software power down. The LRCK also is the synchronization
signal for DIN and represents the sampling rate of the DAC. All registers, including those pertaining to audio functionality,
are only configured via the SPI bus.
D DAC SAMPLING RATE
The audio-control-1 register (Register 00H, Page 2) determines the sampling rates of DAC, which is scaled down from
the reference rate (Fsref) of either 44.1 kHz or 48 kHz, which is selectable by bit D13 of control register 06H/Page2. The
frequency of the LRCK represents the sampling rate of the DAC. At power up, it is configured as an I2S SLAVE with the
DAC operating at Fsref.
D WORD SELECT SIGNALS
The word select signal (LRCK) indicates the channel being transmitted:
−
−
LRCK = 0: left channel for I2S mode
LRCK = 1: right channel for I2S mode
For other modes, check the timing diagrams below.
D 256−S TRANSFER MODE
In the 256-S mode, the BCLK rate always equals 256 times the LRCK frequency. In the 256-S transfer mode, the
combination of the 48-ksps sampling rate and left-justified mode is not supported.
D CONTINUOUS TRANSFER MODE
In continuous transfer mode, the BCLK rate always equals two times the word length times the LRCK frequency.
D RIGHT-JUSTIFIED MODE
In right-justified mode, the LSB of the left channel is valid on the rising edge of the BCLK preceding the falling edge of
LRCK. Similarly, the LSB of the right channel is valid on the rising edge of the BCLK preceding the rising edge of LRCK.
1/fs
LRCK
BCLK
Left Channel
DIN
0
n
MSB
n−1 n−2
Right Channel
2
1
0
n
n−1 n−2
2
LSB
Figure 18. Timing Diagram for Right-Justified Mode
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D LEFT-JUSTIFIED MODE
In left−justified mode, the MSB of the right channel is valid on the rising edge of the BCLK following the falling edge of
LRCK. Similarly the MSB of the left channel is valid on the rising edge of the BCLK following the rising edge of LRCK.
1/fs
LRCK
BCLK
Left Channel
DIN
n
n−1 n−2
2
1
MSB
Right Channel
0
n
n−1 n−2
2
1
0
n
n−1
LSB
Figure 19. Timing Diagram for Left-Justified Mode
D I2S MODE
In I2S mode, the MSB of the left channel is valid on the second rising edge of the BCLK after the falling edge of LRCK.
Similarly, the MSB of the right channel is valid on the second rising edge of the BCLK after the rising edge of LRCK.
1/fs
LRCK
BCLK
1 clock before MSB
Left Channel
DIN
n
n−1 n−2
2
Right Channel
1
MSB
0
n
n−1 n−2
2
1
0
n
LSB
Figure 20. Timing Diagram for I2S Mode
D DSP MODE
In DSP mode, the falling edge of LRCK starts the data transfer with the left channel data first and immediately followed
by the right channel data. Each data bit is valid on the falling edge of BCLK.
1/fs
LRCK
BCLK
Left Channel
DIN
1
0
n
LSB MSB
n−1 n−2
2
Right Channel
1
0
n
n−1 n−2
2
1
LSB MSB
0
n
n−1 n−2
LSB MSB
Figure 21. Timing Diagram for DSP Mode
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STEREO AUDIO DAC
The TSC2102 includes a stereo audio DAC, which can operate with a maximum sampling rate of 48 kHz and can support
all standard audio rates of 8 kHz, 11.025 kHz, 12 kHz, 16kHz, 22.05 kHz, 24 kHz, 32 kHz, 44.1 kHz, and 48 kHz.
When the DAC is operating, the TSC2102 requires an audio MCLK input applied. The user is required to set D13 of control
register 06H/Page2 to indicate which Fsref rate is being used. If the DAC is powered up, then the touch screen ADC runs
off the MCLK and BCLK, and the internal oscillator is powered down to save power.
Each channel of the stereo audio DAC consists of a digital audio processing block, a digital interpolation filter, digital
delta-sigma modulator, and analog reconstruction filter. The DAC is designed to provide enhanced performance at low
sample rates through increased oversampling and image filtering, thereby keeping quantization noise generated within the
delta-sigma modulator and signal images strongly suppressed within the audio band to beyond 20 kHz. This is realized
by keeping the upsampled rate constant at 128 x Fsref and changing the oversampling ratio as the input sample rate is
changed. For Fsref of 48 kHz, the digital delta-sigma modulator always operates at a rate of 6.144 MHz. This ensures that
quantization noise generated within the delta-sigma modulator stays low within the frequency band below 20 kHz at all
sample rates. Similarly, for Fsref rate of 44.1 kHz, the digital delta-sigma modulator always operates at a rate of 5.6448
MHz.
PLL
The TSC2102 has an on chip PLL to generate the needed internal audio clocks from the clock available in the system. The
PLL supports a MCLK varying from 2 MHz to 50 MHz and is register programmable to enable generation of the required
sampling rates from a wide range of system clocks.
The DAC sampling rate is given by:
DAC_FS = Fsref/N
where, Fsref is 44.1 kHz or 48 kHz and N =1, 1.5, 2, 3, 4, 5, 6 are register programmable.
The PLL can be enabled or disabled using register programmability.
D
When PLL is disabled
Fsref + MCLK
128 Q
Q = 2, 3…17
D
When PLL is enabled
Fsref + MCLK
2048
K
P
P = 1, 2, 3, …, 8
K = J.D
J = 1, 2, 3, ….,64
D = 0, 1, 2, …, 9999
where, D is the 4-digit fractional part of K with lagging zeros (e.g. if K = 8.5, then D = 5000 and if K = 8.02, then D = 200).
P, J and D are register programmable.
D
When D = 0, the following condition needs to be satisfied
2 MHz v MCLK v 20 MHz
P
D
When D ≠ 0, the following condition needs to be satisfied
10 MHz v MCLK v 20 MHz
P
Example 1:
For MCLK = 12 MHz and Fsref = 44.1 kHz
P = 1, K = 7.5264
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Example 2:
For MCLK = 12 MHz and Fsref = 48.0 kHz
P = 1, K = 8.192
⇒ J = 8, D = 1920
Digital Audio Processing
The DAC channel consists of optional filters for de-emphasis and bass, treble, midrange level adjustment, or speaker
equalization. The de-emphasis function is only available for sample rates of 32 kHz, 44.1 kHz, and 48 kHz. The transfer
function consists of a pole with time constant of 50 µs and a zero with time constant of 15 µs. Frequency response plots
are given in the Audio Codec Filter Frequency Responses section of this data sheet.
The DAC digital effects processing block also includes a fourth order digital IIR filter with programmable coefficients (one
set per channel). The filter is implemented as cascade of two biquad sections with frequency response given by:
ǒ
Ǔǒ
N0 ) 2 N1 z *1 ) N2 z *2
32768 * 2 D1 z *1 * D2 z *2
Ǔ
N3 ) 2 N4 z *1 ) N5 z *2
32768 * 2 D4 z *1 * D5 z *2
The N and D coefficients are fully programmable, and the entire filter can be enabled or bypassed. The coefficients for this
filter implement a variety of sound effects with bass boost or treble boost as the most commonly used in portable audio
applications. The default N and D coefficients in the part are given by:
N0 = N3 = 27619
N1 = N4 = −27034
N2 = N5 = 26461
D1 = D4 = 32131
D2 = D5 = −31506
and implement a shelving filter with 0-dB gain from dc to approximately 150 Hz, at which point it rolls off to 3-dB attenuation
for higher frequency signals, thus giving a 3-dB boost to signals below 150 Hz. The N and D coefficients are represented
by 16-bit twos complement numbers with values ranging from 32767 to −32768. Frequency response plots are given in
the Audio Codec Filter Frequency Responses section of this data sheet.
Interpolation Filter
The interpolation filter upsamples the output of the digital audio processing block by the required oversampling ratio. It
provides a linear phase output with a group delay of 21/Fs.
In addition, the digital interpolation filter provides enhanced image filtering to reduce signal images caused by the
upsampling process that are below 20 kHz. For example, upsampling an 8-kHz signal produces signal images at multiples
of 8 kHz, i.e., 8 kHz, 16 kHz, 24 kHz, etc. The images at 8 kHz and 16 kHz are below 20 kHz and still audible to the listener,
therefore, they must be filtered heavily to maintain a good quality output. The interpolation filter is designed to maintain at
least 65-dB rejection of images that land below 7.455 Fs. Passband ripple for all sample-rate cases (from 20 Hz to 0.45 Fs)
is ±0.06 dB maximum
Delta-Sigma DAC
The audio digital-to-analog converter incorporates a third order multibit delta-sigma modulator with
768/512/384/256/192/128 times oversampling followed by an analog reconstruction filter. The DAC provides
high-resolution, low-noise performance, using oversampling and noise shaping techniques. The analog reconstruction
filter design consists of a 6 tap analog FIR filter followed by a continuous time RC filter. The analog FIR operates at 6.144
MHz (128x48 kHz, for Fsref of 48 kHz) or at 5.6448 MHz (128x44.1 kHz, for Fsref of 44.1 kHz). The DAC analog
performance can be degraded by excessive clock jitter on the MCLK input. Therefore, care must be taken to keep jitter on
this clock to a minimum.
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DAC Digital Volume Control
The DAC has a digital volume control block, which implements a programmable gain. The volume level can be varied from
0dB to –63.5 dB in 0.5 dB steps, in addition to a mute bit, independently for each channel. The volume level of both channels
can also be changed simultaneously by the master volume control. The gain is implemented with a soft-stepping algorithm,
which only changes the actual volume by one step per input sample, either up or down, until the desired volume is reached.
The rate of soft-stepping can be slowed to one step per two input samples through D1 of control register 04H/Page2.
Because of soft-stepping, the host does not know when the DAC has actually been muted. This may be important if the
host wishes to mute the DAC before making a significant change, such as changing sample rates. In order to help with this
situation, the part provides a flag back to the host via a read-only register bit (D2−D3 of control register 04H/Page2) that
alerts the host when the part has completed the soft-stepping and the actual volume has reached the desired volume level.
The TSC2102 also includes functionality to detect when the user switches on or off the de-emphasis or bass-boost
functions, then first (1) soft-mute the DAC volume control, (2) change the operation of the digital effects processing, and
(3) soft-unmute the TSC2102. This avoids any possible pop/clicks in the audio output due to instantaneous changes in the
filtering. A similar algorithm is used when first powering up or down the DAC. The circuit begins operation at power up with
the volume control muted, then soft-steps it up to the desired volume level. At power down, the logic first soft-steps the
volume down to a mute level, then powers down the circuitry.
Headphone Driver
The TSC2102 features a stereo headphone driver that can deliver 25 mW per channel at 3.3-V supply, into 16-Ω load. The
headphones can be connected in a single-ended configuration using ac-coupling capacitors, or the capacitors can be
removed and virtual ground (VGND) connection powered. These two configurations are shown in Figure 22. If the
headphone amplifiers are not needed, such as when the external audio amplifier is used, then the headphone drivers can
be bypassed to save power using register programming. When bypassed, the HPR and HPL outputs act as line level
outputs capable of driving a load of 10 kΩ minimum.
VIRTUAL−GROUND
SINGLE−ENDED
SPEAKER CONNECTION
SPEAKER CONNECTION
HPR
+
HPR
+
VGND
HPL
+
+
HPL
Figure 22. Connection Diagram for DAC Outputs
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KEYCLICK
A special circuit has also been included for inserting a square-wave signal into the analog output signal path based on
register control. This functionality is intended for generating keyclick sounds for user feedback. Register 04H/Page2
contains bits that control the amplitude, frequency, and duration of the square−wave signal. The frequency of the signal
can be varied from 62.5 Hz to 8 kHz and its duration can be programmed from 2 periods to 32 periods. Whenever this
register is written, the square wave is generated and coupled into the audio output, going to both the outputs. The keyclick
enable bit D15 of control register 04H/Page2 is reset after the duration of keyclick is played out. This capability is available
even when the DAC is powered down.
SPI DIGITAL INTERFACE
All TSC2102 control registers are programmed through a standard SPI bus. The SPI allows full-duplex, synchronous, serial
communication between a host processor (the master) and peripheral devices (slaves). The SPI master generates the
synchronizing clock and initiates transmissions. The SPI slave devices depend on a master to start and synchronize
transmissions.
A transmission begins when initiated by a master SPI. The byte from the master SPI begins shifting in on the slave SPIDIN
(MOSI) pin under the control of the master serial clock. As the byte shifts in on the SPIDIN pin, a byte shifts out on the
SPIDOUT (MISO) pin to the master shift register.
The idle state of the serial clock for the TSC2102 is low, which corresponds to a clock polarity setting of 0 (typical
microprocessor SPI control bit CPOL = 0). The TSC2102 interface is designed so that with a clock phase bit setting of 1
(typical microprocessor SPI control bit CPHA = 1), the master begins driving its MOSI pin and the slave begins driving its
SPIDOUT pin on the first serial clock edge. The SS pin can remain low between transmissions; however, the TSC2102
only interprets command words which are transmitted after the falling edge of SS.
TSC2102 COMMUNICATION PROTOCOL
Register Programming
The TSC2102 is entirely controlled by registers. Reading and writing these registers is controlled by an SPI master and
accomplished by the use of a 16-bit command, which is sent prior to the data for that register. The command is constructed
as shown in Figure 23.
The command word begins with a R/W bit, which specifies the direction of data flow on the SPI serial bus. The following
4 bits specify the page of memory this command is directed to, as shown in Table 2. The next six bits specify the register
address on that page of memory to which the data is directed. The last five bits are reserved for future use and should be
written only with zeros.
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Table 2. Page Addressing
PG3
PG2
PG1
PG0
PAGE ADDRESSED
0
0
0
0
0
0
0
0
1
1
0
0
1
0
2
0
0
1
1
Reserved
0
1
0
0
Reserved
0
1
0
1
Reserved
0
1
1
0
Reserved
0
1
1
1
Reserved
1
0
0
0
Reserved
1
0
0
1
Reserved
1
0
1
0
Reserved
1
0
1
1
Reserved
1
1
0
0
Reserved
1
1
0
1
Reserved
1
1
1
0
Reserved
1
1
1
1
Reserved
To read all the first page of memory, for example, the host processor must send the TSC2102 the command 0x8000 – this
specifies a read operation beginning at page 0, address 0. The processor can then start clocking data out of the TSC2102.
The TSC2102 automatically increments its address pointer to the end of the page; if the host processor continues clocking
data out past the end of a page, the TSC2102 sends back the value 0xFFFF.
Likewise, writing to page 1 of memory consists of the processor writing the command 0x0800, which specifies a write
operation, with PG0 set to 1, and all the ADDR bits set to 0. This results in the address pointer pointing at the first location
in memory on Page 1. See the section on the TSC2102 memory map for details of register locations
BIT 15
MSB
BIT 14
BIT 13
BIT 12
BIT 11
BIT 10
BIT 9
BIT 8
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
LSB
R/W*
PG3
PG2
PG1
PG0
ADDR5
ADDR4
ADDR3
ADDR2
ADDR1
ADDR0
0
0
0
0
0
Figure 23. TSC2102 Command Word
SS
SCLK
MOSI
COMMAND WORD
DATA
Figure 24. Write Operation for TSC2102 SPI Interface
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SS
SCLK
MOSI
COMMAND WORD
MISO
DATA
DATA
Figure 25. Read Operation for TSC2102 SPI Interface
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TSC2102 MEMORY MAP
The TSC2102 has several 16-bit registers, which allow control of the device as well as providing a location for results from
the TSC2102 to be stored until read by the host microprocessor. These registers are separated into three pages of memory
in the TSC2102: a data page (Page 0) and control pages (Page 1 and Page 2). The memory map is shown in Table 3.
Table 3. Memory Map
Page 0: Touch Screen Data Registers
ADDR
Page 1: Touch Screen Control Registers
REGISTER
ADDR
REGISTER
Page 2: Audio Control Registers
ADDR
REGISTER
00
X
00
TSC ADC
00
Audio Control 1
01
Y
01
Status
01
Reserved
02
Z1
02
Reserved
02
DAC Volume Control
03
Z2
03
Reference
03
Reserved
04
Reserved
04
Reset
04
Audio Control 2
05
BAT1
05
Configuration
05
Stereo DAC Power Control
06
BAT2
06
Reserved
06
Audio Control 3
07
AUX
07
Reserved
07
Audio Bass−Boost Filter Coefficients
08
Reserved
08
Reserved
08
Audio Bass−Boost Filter Coefficients
09
TEMP1
09
Reserved
09
Audio Bass−Boost Filter Coefficients
0A
TEMP2
0A
Reserved
0A
Audio Bass−Boost Filter Coefficients
0B
Reserved
0B
Reserved
0B
Audio Bass−Boost Filter Coefficients
0C
Reserved
0C
Reserved
0C
Audio Bass−Boost Filter Coefficients
0D
Reserved
0D
Reserved
0D
Audio Bass−Boost Filter Coefficients
0E
Reserved
0E
Reserved
0E
Audio Bass−Boost Filter Coefficients
0F
Reserved
0F
Reserved
0F
Audio Bass−Boost Filter Coefficients
10
Reserved
10
Reserved
10
Audio Bass−Boost Filter Coefficients
11
Reserved
11
Reserved
11
Audio Bass−Boost Filter Coefficients
12
Reserved
12
Reserved
12
Audio Bass−Boost Filter Coefficients
13
Reserved
13
Reserved
13
Audio Bass−Boost Filter Coefficients
14
Reserved
14
Reserved
14
Audio Bass−Boost Filter Coefficients
15
Reserved
15
Reserved
15
Audio Bass−Boost Filter Coefficients
16
Reserved
16
Reserved
16
Audio Bass−Boost Filter Coefficients
17
Reserved
17
Reserved
17
Audio Bass−Boost Filter Coefficients
18
Reserved
18
Reserved
18
Audio Bass−Boost Filter Coefficients
19
Reserved
19
Reserved
19
Audio Bass−Boost Filter Coefficients
1A
Reserved
1A
Reserved
1A
Audio Bass−Boost Filter Coefficients
1B
Reserved
1B
Reserved
1B
PLL Programmability
1C
Reserved
1C
Reserved
1C
PLL Programmability
1D
Reserved
1D
Reserved
1D
Audio Control 4
1E
Reserved
1E
Reserved
1E
Reserved
1F
Reserved
1F
Reserved
1F
Reserved
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TSC2102 CONTROL REGISTERS
This section describes each of the registers shown in the memory map of Table 3. The registers are grouped according
to the function they control. In the TSC2102, bits in control registers can refer to slightly different functions depending upon
whether you are reading the register or writing to the register.
TSC2102 Data Registers (Page 0)
The data registers of the TSC2102 hold data results from conversion performed by the touch screen ADC. All of these
registers default to 0000H upon reset. These registers are read only.
X, Y, Z1, Z2, BAT1, BAT2, AUX, TEMP1 and TEMP2 Registers
The results of all A/D conversions are placed in the appropriate data register. The data format of the result word, R, of these
registers is right-justified, as follows:
BIT 15
MSB
BIT 14
BIT 13
BIT 12
BIT 11
BIT 10
BIT 9
BIT 8
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
LSB
0
0
0
0
R11
MSB
R10
R9
R8
R7
R6
R5
R4
R3
R2
R1
R0
LSB
PAGE 1 CONTROL REGISTER MAP
REGISTER 00H: Touch Screen ADC Control
BIT
NAME
READ/
WRITE
D15
PSTCM
R/W
0(for read status)
0(for write status)
Pen Status/Control Mode.
READ
0 => There is no screen touch (default)
1 => The pen is down
WRITE
0 => Host controlled touch screen conversions(default).
1=> TSC2102 controlled touch screen conversions.
D14
ADST
R/W
1(for read status)
0(for write status)
A/D Status.
READ
0 => ADC is busy
1 => ADC is not busy (default)
WRITE
0 => Normal mode. (default)
1 => Stop conversion and power down. Power down happens immediately
RESET VALUE
FUNCTION
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BIT
NAME
READ/
WRITE
RESET VALUE
FUNCTION
D13−10
ADSCM
R/W
0000
A/D Scan Mode.
0000 => No scan
0001 => Touch screen scan function: X and Y coordinates are converted and the results
returned to X and Y data registers. Scan continues until either the pen is lifted
or a stop bit is sent.
0010 => Touch screen scan function: X, Y, Z1 and Z2 coordinates are converted and the
results returned to X, Y, Z1 and Z2 data registers. Scan continues until either
the pen is lifted or a stop bit is sent.
0011 => Touch screen scan function: X coordinate is converted and the results returned
to X data register.
0100 => Touch screen scan function: Y coordinate is converted and the results returned
to Y data register.
0101 => Touch screen scan function: Z1 and Z2 coordinates are converted and the results
returned to Z1 and Z2 data registers.
0110 => BAT1 input is converted and the result is returned to the BAT1 data register.
0111 => BAT2 input is converted and the result is returned to the BAT2 data register.
1000 => AUX input is converted and the result is returned to the AUX data register.
1001 => Scan function :AUX input is converted and the result is returned to the AUX data
register. Scan continues until stop bit is sent.
1010 => TEMP1 is converted and the result is returned to the TEMP1 data register.
1011 => Port scan function: BAT1, BAT2 and AUX inputs are measured and the results
returned to the appropriate data registers.
1100 => TEMP2 is converted and the result is returned to the TEMP2 data register.
1101 => Turn on X+, X− drivers
1110 => Turn on Y+, Y− drivers
1111 => Turn on Y+, X− drivers
D9−D8
RESOL
R/W
00
Resolution Control. The A/D converter resolution is specified with these bits.
00 => 12−bit resolution
01 => 8−bit resolution
10 => 10−bit resolution
11 => 12−bit resolution
D7−D6
ADAVG
R/W
00
Converter Averaging Control. These two bits allow you to specify the number of averages
the converter performs selected by bit D0, which selects either mean filter or
median filter.
Mean Filter
Median filter
00 => No average
No average
01 => 4−data average
5-data average
10 => 8−data average
9-data average
11 => 16−data average
15-data average
D5−D4
ADCR
R/W
00
Conversion Rate Control. These two bits specify the internal clock rate which the A/D
converter uses to perform a single conversion. These bits are the same
whether reading or writing.
tconv + N ) 4
ƒ
INTCLK
where fINTCLK is the internal clock frequency. For example, with 12-bit resolution and a
2-MHz internal clock frequency, the conversion time is 8.0 µs. This yields an effective
throughput rate of 125 kHz.
00 => 8-MHz internal clock rate (use for 8-bit resolution only)
01 => 4-MHz internal clock rate (use for 8-bit/10-bit resolution only)
10 => 2-MHz internal clock rate
11 => 1-MHz internal clock rate
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BIT
NAME
READ/
WRITE
RESET VALUE
FUNCTION
D3−D1
PVSTC
R/W
000
Panel Voltage Stabilization Time Control. These bits allow you to specify a delay time from
the time the touch screen drivers are enabled to the time the voltage is sampled and a
conversion is started. This allows the user to adjust for the settling of the individual touch
panel and external capacitances.
000 => 0-µs stabilization time
001 => 100-µs stabilization time
010 => 500-µs stabilization time
011 => 1-ms stabilization time
100 => 5-ms stabilization time
101 => 10-ms stabilization time
110 => 50-ms stabilization time
111 => 100-ms stabilization time
D0
AVGFS
R/W
0
Average Filter select
0 => Mean filter
1 => Median filter
REGISTER 01H: Status Register
BIT
NAME
D15−D14 PINTDAV
READ/
WRITE
RESET
VALUE
R/W
10
FUNCTION
Pen Interrupt or Data Available. These two bits program the function of the PINTDAV pin.
00 => Acts as PEN interrupt (active low) only. When PEN touch is detected, PINTDAV goes low.
01 => Acts as data available (active low) only. The PINTDAV goes low as soon as one set of ADC
conversion(s) is completed. For scan mode, PINTDAV remains low as long as all the
appropriate registers have not been read out.
10 => Acts as both PEN interrupt and data available. When PEN touch is detected, PINTDAV goes
low. PINTDAV goes high once all the selected conversions are over.
11 => Same as 10
Note: See the section Conversion Time Calculation for the TSC2102 in this data sheet for timing
diagrams and conversion time calculations.
D13
PWRDN
R
0
TSC−ADC Power down status
0 => TSC−ADC is active
1 => TSC−ADC stops conversion and powers down
D12
HCTLM
R
0
Host Controlled Mode Status
0 => Host controlled mode
1 => Self (TSC2102) controlled mode
D11
DAVAIL
R
0
Data Available Status
0 => No data available.
1 => Data is available(i.e one set of conversion is done)
Note:− This bit gets cleared only after all the converted data have been completely read out.
D10
XSTAT
R
0
X Data Register Status
0 => No new data is available in X−data register
1 => New data for X−coordinate is available in register
Note: This bit gets cleared only after the converted data of X coordinate has been completely read
out of the register.
D9
YSTAT
R
0
Y Data Register Status
0 => No new data is available in Y−data register
1 => New data for Y−coordinate is available in register
Note: This bit gets cleared only after the converted data of Y coordinate has been completely read
out of the register.
D8
Z1STAT
R
0
Z1 Data Register Status
0 => No new data is available in Z1−data register
1 => New data is available in Z1−data register
Note: This bit gets cleared only after the converted data of Z1 coordinate has been completely read
out of the register.
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BIT
NAME
READ/
WRITE
RESET
VALUE
D7
Z2STAT
R
0
FUNCTION
Z2 Data Register Status
0 => No new data is available in Z2−data register
1 => New data is available in Z2−data register
Note: This bit gets cleared only after the converted data of Z2 coordinate has been completely read
out of the register.
D6
B1STAT
R
0
BAT1 Data Register Status
0 => No new data is available in BAT1−data register
1 => New data is available in BAT1−data register
Note: This bit gets cleared only after the converted data of BAT1 has been completely read out of
the register.
D5
B2STAT
R
0
BAT2 Data Register Status
0 => No new data is available in BAT2−data register
1 => New data is available in BAT2−data register
Note: This bit gets cleared only after the converted data of BAT2 has been completely read out of
the register.
D4
AXSTAT
R
0
AUX Data Register Status
0 => No new data is available in AUX−data register
1 => New data is available in AUX−data register
Note: This bit gets cleared only after the converted data of AUX has been completely read out of the
register.
D3
D2
T1STAT
R
0
Reserved
R
0
TEMP1 Data Register Status
0 => No new data is available in TEMP1−data register
1 => New data is available in TEMP1−data register
Note: This bit gets cleared only after the converted data of TEMP1 has been completely read out of
the register.
D1
T2STAT
R
0
TEMP2 Data Register Status
0 => No new data is available in TEMP2−data register
1 => New data is available in TEMP2−data register
Note: This bit gets cleared only after the converted data of TEMP2 has been completely read out of
the register.
D0
R
0
Reserved
REGISTER 02H: Reserved
BIT
NAME
D15−D0
READ/
WRITE
RESET
VALUE
R
FFFFH
FUNCTION
Reserved
REGISTER 03H: Reference Control
NAME
READ/
WRITE
RESET
VALUE
R
000H
D4
VREFM
R/W
0
Voltage Reference Mode. This bit configures the VREF pin as either external reference or internal
reference.
0 => External reference
1 => Internal reference
D3−D2
RPWUDL
R/W
00
Reference Power Up Delay. These bits allow for a delay time for measurements to be made after
the reference powers up, thereby assuring that the reference has settled
00 => 0 µs
01 => 100 µs
10 => 500 µs
11 => 1000 µs
Note: This is valid only when the device is programmed for internal reference and Bit D1 = 1, i.e.,
reference is powered down between the conversions if not required.
BIT
D15−D5
34
FUNCTION
Reserved
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BIT
NAME
READ/
WRITE
RESET
VALUE
D1
RPWDN
R/W
1
Reference Power Down. This bit controls the power down of the internal reference voltage.
0 => Powered up at all times.
1 => Powered down between conversions.
Note: when D4 = 0, i.e. device is in external reference mode, then the internal reference is powered
down always.
D0
IREFV
R/W
0
Internal Reference Voltage. This bit selects the internal voltage reference level for the TSC ADC.
0 => VREF = 1.25 V
1 => VREF = 2.50 V
FUNCTION
REGISTER 04H: Reset Control
BIT
NAME
READ/
WRITE
RESET
VALUE
D15−D0
RSALL
R/W
FFFFH
FUNCTION
Reset All. Writing the code 0xBB00, as shown below, to this register causes the TSC2102 to reset
all its registers to their default, power−up values.
1011101100000000 => Reset all registers
Others
=> Do not write other sequences to this register.
REGISTER 05H: Configuration Control
NAME
READ/
WRITE
RESET
VALUE
R
000H
D5−D3
PRECTM
R/W
000
Precharge Time. These bits set the amount of time allowed for precharging any pin capacitance on
the touch screen prior to sensing if a screen touch is happening.
000 => 20 µs
001 => 84 µs
010 => 276 µs
011 => 340 µs
100 => 1.044 ms
101 => 1.108 ms
110 => 1.300 ms
111 => 1.364 ms
D2−D0
RPWUDL
R/W
000
Sense Time. These bits set the amount of time the TSC2102 waits to sense whether the screen is
being touched, when converting a coordinate value.
000 => 32 µs
001 => 96 µs
010 => 544 µs
011 => 608 µs
100 => 2.080 ms
101 => 2.144 ms
110 => 2.592 ms
111 => 2.656 ms
BIT
D15−D6
FUNCTION
Reserved. Write only zeros to these bits.
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PAGE 2 CONTROL REGISTER MAP
REGISTER 00H: Audio Control 1
NAME
READ/
WRITE
RESET
VALUE
R
0000
D11−D10
WLEN
R/W
00
Codec Word Length
00 => Word length = 16 bit
01 => Word length = 20 bit
10 => Word length = 24 bit
11 => Word length = 32 bit
D9−D8
DATFM
R/W
00
Digital Data Format
00 => I2S mode
01 => DSP mode
10 => Right justified
11 => Left justified
R
00
Reserved. Write only 00 to this location.
DACFS
R/W
000
DAC Sampling Rate
000000 => DAC FS = Fsref/1
001001 => DAC FS = Fsref/(1.5)
010010 => DAC FS = Fsref/2
011011=> DAC FS = Fsref/3
100100 => DAC FS = Fsref/4
101101 => DAC FS = Fsref/5
110110 => DAC FS = Fsref/6
111111 => DAC FS = Fsref/6
others => Not allowed
Note: Fsref is either 48 kHz or 44.1 kHz
BIT
D15−D12
D7−D6
D5−D0
FUNCTION
Reserved. Write only 0000 to this location.
REGISTER 01H: Reserved
BIT
NAME
D15−D0
READ/
WRITE
RESET
VALUE
R
FF00H
FUNCTION
Reserved. Write only FF00H to this location.
REGISTER 02H: DAC Volume Control
BIT
NAME
READ/
WRITE
RESET
VALUE
D15
DALMU
R/W
1
D14−D8
DALVL
R/W
1111111
FUNCTION
DAC Left Channel Mute
1 => DAC left channel muted
0 => DAC left channel not muted
DAC Left Channel Volume Control
1111111 => DAC left channel Vol = 0 dB
0000001 => DAC left channel Vol = −0.5 dB
0000010 => DAC left channel Vol = −1.0 dB
1111101 => DAC left channel Vol = −62.5 dB
1111110 => DAC left channel Vol = −63.0 dB
0000000 => DAC left channel Vol = −63.5 dB
D7
DARMU
R/W
1
D6−D0
DARVL
R/W
1111111
DAC Right Channel Mute
1 => DAC right channel muted
0 => DAC right channel not muted
DAC Right Channel Volume Control
1111111 => DAC right channel Vol = 0 dB
0000001 => DAC right channel Vol = −0.5 dB
0000010 => DAC right channel Vol = −1.0 dB
1111101 => DAC right channel Vol = −62.5 dB
1111110 => DAC right channel Vol = −63.0 dB
0000000 => DAC right channel Vol = −63.5 dB
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REGISTER 03H: Reserved
BIT
NAME
READ/
WRITE
D15−D0
R
RESET
VALUE
FUNCTION
1000101100000000 Reserved. Write only 8B00H to this location.
REGISTER 04H: Audio Control 2
BIT
NAME
READ/
WRITE
RESET
VALUE
D15
KCLEN
R/W
0
D14−D12
KCLAC
R/W
100
FUNCTION
Keyclick Enable
0 => Keyclick disabled
1 => Keyclick enabled
Note: This bit is automatically cleared after giving out the keyclick signal length equal to the
programmed value.
Keyclick Amplitude Control
000 => Lowest amplitude
100 => Medium amplitude
111 => Highest amplitude
D11
R
0
Reserved. Write only 0 to this location.
D10−D8
KCLFRQ
R/W
100
Keyclick Frequency
000 => 62.5Hz
001 => 125Hz
010 => 250Hz
011 => 500Hz
100 => 1kHz
101 => 2kHz
110 => 4kHz
111 => 8kHz
D7−D4
KCLLN
R/W
0001
Keyclick Length
0000 => 2 periods key click
0001 => 4 periods key click
0010 => 6 periods key click
0011 => 8 periods key click
all other values => 32 periods key click
D3
DLGAF
R
0
DAC Left Channel PGA Flag ( Read Only )
0 => Gain applied /= PGA register setting
1 => Gain applied = PGA register setting.
Note: This flag indicates when the soft-stepping for DAC left channel is completed
D2
DRGAF
R
0
DAC Right Channel PGA Flag ( Read Only )
0 => Gain applied /= PGA register setting
1 => Gain applied = PGA register setting.
Note: This flag indicates when the soft-stepping for DAC right channel is completed
D1
DASTC
R/W
0
DAC Channel PGA Soft-Stepping Control
0 => 0.5dB change every LRCK
1 => 0.5dB change every 2 LRCK
R
0
Reserved. Write only 0 to this location.
D0
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REGISTER 05H: Stereo DAC Power Control
BIT
NAME
READ/
WRITE
RESET
VALUE
D15
PWDNC
R/W
1
Codec Power-Down Control
0 => Codec powered up
1 => Codec powered down
R
01
Reserved. Write only 01 to this location.
DAODRC
R/W
0
DAC Output Driver Control
0 => Headphone driver bypassed
1 => Headphone driver enabled
R
1
Reserved. Write only 1 to this location.
DAPWDN
R/W
1
DAC Power-Down Control
0 => Power up the DAC
1 => Power down the DAC
R
1
Reserved. Write only 1 to this location.
VGPWDN
R/W
1
Driver Virtual Ground Power Down
0 => Power up the VGND amp
1 => Power down the VGND amp
R
1
Reserved. Write only 1 to this location.
R
1
DAC Power-Down Flag
0 => DAC power down is not complete
1 => DAC power down is complete
R
1000
Reserved. Write only 1000 to this location.
D14−D13
D12
D11
D10
D9
D8
D7
D6
DAPWDF
D5−D2
38
FUNCTION
D1
BASSBC
R/W
0
Bass Boost Control
0 => Disable bass boost filter
1 => Enable bass boost filter
D0
DEEMPF
R/W
0
De−Emphasis Filter Enable
0 => Disable de-emphasis filter
1 => Enable de-emphasis filter
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REGISTER 06H: Audio Control 3
BIT
NAME
READ/
WRITE
RESET
VALUE
D15−D14
DMSVOL
R/W
00
DAC Channel Master Volume Control
00 => Left channel and right channel have independent volume controls.
01 => Left channel volume control is the programmed value of the right channel volume control.
10 => Right channel volume control is the programmed value of the left channel volume control.
11 => same as 00
D13
REFFS
R/W
0
Reference Sampling Rate
0 => Fsref = 48.0kHz
1 => Fsref = 44.1kHz
D12
DAXFM
R/W
0
Master Transfer Mode
0 => Continuous data transfer mode
1 => 256−s data transfer mode
D11
SLVMS
R/W
0
Audio Master Slave Selection
0 => TSC2102 is slave DAC
1 => TSC2102 is master DAC
D10−D8
FUNCTION
R
000
D7
DALOVF
R
0
DAC Left Channel Overflow Flag ( Read Only )
0 => DAC left channel data is within saturation limits
1 => DAC left channel data has exceeded saturation limits
Note : Once this flag is set to 1, it gets cleared only when user reads this register.
D6
DAROVF
R
0
DAC Right Channel Overflow Flag ( Read Only )
RESET VAL = 0
0 => DAC right channel data is within saturation limits
1 => DAC right channel data has exceeded saturation limits
Note : Once this flag is set to 1, it is cleared only when user reads this register
R
000
Reserved. Write only 000 to this location.
R
001
Revision ID. This field represents the silicon revision and should always read 001.
D5−D3
D2−D0
REVID
Reserved. Write only 000 to this location.
REGISTER 07H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
L_N0
R/W
27619
FUNCTION
Left channel bass-boost coefficient N0.
REGISTER 08H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
L_N1
R/W
−27034
FUNCTION
Left channel bass-boost coefficient N1.
REGISTER 09H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
L_N2
R/W
26461
FUNCTION
Left channel bass-boost coefficient N2.
REGISTER 0AH: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
L_N3
R/W
27619
FUNCTION
Left channel bass-boost coefficient N3.
REGISTER 0BH: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
L_N4
R/W
−27034
FUNCTION
Left channel bass-boost coefficient N4.
REGISTER 0CH: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
L_N5
R/W
26461
FUNCTION
Left channel bass-boost coefficient N5.
39
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REGISTER 0DH: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
L_D1
R/W
32131
FUNCTION
Left channel bass-boost coefficient D1.
REGISTER 0EH: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
L_D2
R/W
−31506
FUNCTION
Left channel bass-boost coefficient D2.
REGISTER 0FH: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
L_D4
R/W
32131
FUNCTION
Left channel bass-boost coefficient D4.
REGISTER 10H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
L_D5
R/W
−31506
FUNCTION
Left channel bass-boost coefficient D5.
REGISTER 11H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
R_N0
R/W
27619
FUNCTION
Right channel bass-boost coefficient N0.
REGISTER 12H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
R_N1
R/W
−27034
FUNCTION
Right channel bass-boost coefficient N1.
REGISTER 13H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
R_N2
R/W
26461
FUNCTION
Right channel bass-boost coefficient N2.
REGISTER 14H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
R_N3
R/W
27619
FUNCTION
Right channel bass-boost coefficient N3.
REGISTER 15H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
R_N4
R/W
−27034
FUNCTION
Right channel bass-boost coefficient N4.
REGISTER 16H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
R_N5
R/W
26461
FUNCTION
Right channel bass-boost coefficient N5.
REGISTER 17H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
R_D1
R/W
32131
FUNCTION
Right channel bass-boost coefficient D1.
REGISTER 18H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
R_D2
R/W
−31506
40
FUNCTION
Right channel bass-boost coefficient D2.
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REGISTER 19H: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
R_D4
R/W
32131
FUNCTION
Right channel bass-boost coefficient D4.
REGISTER 1AH: Audio Bass Boost Coefficients
BIT
NAME
READ/
WRITE
RESET VALUE
(IN DECIMAL)
D15−D0
R_D5
R/W
−31506
FUNCTION
Right channel bass-boost coefficient D5.
REGISTER 1BH: PLL Programmability
BIT
NAME
READ/
WRITE
RESET VALUE
D15
PLLEN
R/W
0
D14−D11
QVAL
R/W
0010
FUNCTION
PLL Enable
0 => Disable PLL
1 => Enable PLL
Q value. Valid only if D15 = 0.
0000 => 16
0001 => 1
0010 => 2
1110 => 14
1111 => 15
D10−D8
PVAL
R/W
000
P value. Valid only if D15 = 1.
000=> 8
001=> 1
010 => 2
110 => 6
111 => 7
D7−D2
JVAL
R/W
000001
J value. Valid only if D15 = 1.
000001 => 1
000010 => 2
111101 => 61
111110 => 62
111111 => 63
D1−D0
Reserved
R
00
Reserved. Write only 00 to this location.
REGISTER 1CH: PLL Programmability
BIT
NAME
READ/
WRITE
RESET VALUE
D15−D2
DVAL
R/W
0 (in decimal)
D1−D0
Reserved
R
00
FUNCTION
D value. Used when PLL is enabled.
D value is valid from 0000 to 9999 in decimal.
Programmed value greater than 9999 is treated as 9999
00000000000000 => 0 decimal
00000000000001 => 1 decimal
Reserved (write only 00)
41
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
REGISTER 1DH: Audio Control 4
BIT
NAME
READ/
WRITE
RESET VALUE
D15
Reserved
R
0
Reserved. Write only 0 to this location.
D14
DASTPD
R/W
0
DAC Soft-Stepping Control
0 => Soft-stepping is enabled
1 => Soft-stepping is disabled
D13−D2
Reserved
R
000000000000
D1−D0
Reserved
R
XX
FUNCTION
Reserved. Write only 000000000000 in this location.
Reserved (write only 00)
LAYOUT
The following layout suggestions should provide optimum performance from the TSC2102. However, many portable
applications have conflicting requirements concerning power, cost, size, and weight. In general, most portable devices
have fairly clean power and grounds because most of the internal components are very low power. This situation means
less bypassing for the converter power and less concern regarding grounding. Still, each situation is unique and the
following suggestions should be reviewed carefully.
For optimum performance, care must be taken with the physical layout of the TSC2102 circuitry. The basic SAR architecture
is sensitive to glitches or sudden changes on the power supply, reference, ground connections, and digital inputs that occur
just prior to latching the output of the analog comparator. Therefore, during any single conversion for an n-bit SAR converter,
there are n windows in which large external transient voltages can easily affect the conversion result. Such glitches might
originate from switching power supplies, nearby digital logic, and high power devices. The degree of error in the digital
output depends on the reference voltage, layout, and the exact timing of the external event. The error can change if the
external event changes in time with respect to the timing of the critical n windows.
With this in mind, power to the TSC2102 must be clean and well bypassed. A 0.1-µF ceramic bypass capacitor must be
placed as close to the device as possible. A 1-µF to 10-µF capacitor may also be needed if the impedance between the
TSC2102 supply pins and the system power supply is high.
The VREF pin requires a minimum bypass capacitor of 0.1 µF, although a larger value can be used to reduce the reference
noise level. If an external reference voltage originates from an op-amp, make sure that it can drive any bypass capacitor
that is used without oscillation.
The TSC2102 architecture offers no inherent rejection of noise or voltage variation in regards to using an external reference
input. This is of particular concern when the reference input is tied to the power supply. Any noise and ripple from the supply
appears directly in the digital results. While high frequency noise can be filtered out, voltage variation due to line frequency
(50 Hz or 60 Hz) can be difficult to remove.
The ground pins must be connected to a clean ground point. In many cases, this is the analog ground. Avoid connections
that are too near the grounding point of a microcontroller or digital signal processor. If needed, run a ground trace directly
from the converter to the power supply entry or battery connection point. The ideal layout includes an analog ground plane
dedicated to the converter and associated analog circuitry.
In the specific case of use with a resistive touch screen, care must be taken with the connection between the converter
and the touch screen. Since resistive touch screens have fairly low resistance, the interconnection must be as short and
robust as possible. Loose connections can be a source of error when the contact resistance changes with flexing or
vibrations.
As indicated previously, noise can be a major source of error in touch-screen applications (e.g., applications that require
a back-lit LCD panel). This EMI noise can be coupled through the LCD panel to the touch screen and cause flickering of
the converted ADC data. Several things can be done to reduce this error, such as utilizing a touch screen with a bottom-side
metal layer connected to ground. This couples the majority of noise to ground. Additionally, filtering capacitors, from Y+,
Y–, X+, and X– to ground, can also help. Note, however, that the use of these capacitors increases screen settling time
and requires longer panel voltage stabilization times, as well as increased precharge and sense times for the PINTDAV
circuitry of the TSC2102.
42
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
CONVERSION TIME CALCULATIONS FOR THE TSC2102
Touch Screen Conversion Initiated At Touch Detect
The time needed to get a converted X/Y coordinate for reading can be calculated by (not including the time needed to send
the command over the SPI bus):
t
coordinate
+2
t
ȱǒtPRE ) tSNS ) tPVSǓȳ
ȧ
ȧ
125 ns
Ȳ
ȴ
OSC
) 18
t
OSC
) n2
t
OSC
t
OSC
)2
) n3
t
NJ ƪǒ
N
AVG
N
BITS
Ǔ
)1
ƫ Nj
8 MHz ) n ) 12 ) 1
1
ƒ conv
OSC
where:
tcoordinate = time to convert X/Y coordinate
tPVS = Panel voltage stabilization time
tPRE = precharge time
tSNS = sense time
NAVG = number of averages; for no averaging, NAVG = 1
NBITS = number of bits of resolution
ƒconv = A/D converter clock frequency
tOSC = Oscillator clock period
n1 = 6 ; if ƒconv = 8 MHz
7 ; if ƒconv ≠ 8 MHz
n2 = 4 ; if tPVS = 0 µs
0 ; if tPVS ≠ 0 µs
n3 = 0 ; if tSNS = 32 µs
2 ; if tSNS ≠ 32 µs
NOTE: The above formula is exactly valid only when the audio DAC is powered down. Also, after touch detect, the formula holds true from second
conversion onwards. For continuous touch and D15−D14 = 00/10/11, the high duration of the PINTDAV signal is given by tPRE + tSNS with
an oscillator clock of 8 MHz.
Programmed
for Self
Controlled
X−Y Scan
Mode
Detecting Touch
PINTDAV
(As PENIRQ
[D15−D14 = 00])
PINTDAV
(As DATA_AVA
[D15−D14 = 01])
Reading
X−Data
Register
SS DEACTIVATED
Sample,Conversion &
Averaging for
Y−Coordinate
Touch Is Detected
PINTDAV
(As PENIRQ & DATA_AVA
[D15−D14 = 10/11])
Detecting
Touch
Sample,Conversion &
Averaging for
X−Coordinate
Detecting
Touch
Reading
Y−Data
Register
Sample,Conversion &
Averaging for
Y−Coordinate
Detecting
Touch
Touch Is Detected
Touch Is Detected
43
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
The time for a complete X/Y/Z1/Z2 coordinate conversion is given by(not including the time needed to send the command
over the SPI bus):
t
coordinate
ȱǒtPRE ) tSNS ) tPVSǓȳ
ȧ
ȧ
125 ns
Ȳ
ȴ
+3
t
OSC
) 33
t
OSC
) n2
t
t
OSC
OSC
NJ ƪǒ
)4
) n3
t
N
AVG
N
BITS
Ǔ
)1
ƫ Nj
8 MHz ) n ) 12 ) 1
1
ƒ conv
OSC
n1 = 6 ; if ƒconv = 8 MHz
7 ; if ƒconv ≠ 8 MHz
n2 = 4 ; if tPVS = 0 µs
0 ; if tPVS ≠ 0 µs
n3 = 0 ; if tSNS = 32 µs
3 ; if tSNS ≠ 32 µs
NOTE: The above formula is exactly valid only when the audio DAC is powered down. Also after touch detect the formula holds true from second
conversion onwards. For continuous touch and D15−D14 = 00/10/11, the high duration of the PINTDAV signal is given by tPRE + tSNS with
an oscillator clock of 8 MHz.
Programmed
for Self
Controlled
X−Y−Z1−Z2
Scan
Mode
Reading Reading Reading Reading
X−Data Y−Data Z1−Data Z2−Data
Register Register Register Register
SS DEACTIVATED
Detecting Touch
Sample,Conversion &
Sample,Conversion &
Sample,Conversion &
Detecting
Detecting
Detecting
Averaging for
Averaging for
Averaging for
Touch
Touch
Touch
Y−Coordinate
X−Coordinate
Z1−Coordinate & Z2−Coordinate
Touch Is Detected
Touch Is Detected
Sample,Conversion &
Averaging for
Y−Coordinate
Detecting
Touch
Touch Is Detected
PINTDAV
(As PENIRQ
[D15−D14 = 00])
PINTDAV
(As DATA_AVA
[D15−D14 = 01])
PINTDAV
(As PENIRQ & DATA_AVA
[D15−D14 = 10/11])
Touch Is Detected
Touch Screen Conversion Initiated by the Host
The time needed to convert any single coordinate either X or Y under host control (not including the time needed to send
the command over the SPI bus) is given by:
t
coordinate
ȱǒtPVSǓȳ
ȧ125 nsȧ
Ȳ
ȴ
+
t
OSC
) 14
t
OSC
t
NJ ƪǒ
) N
OSC
AVG
) n2
t
N
BITS
Ǔ
)1
ƫ Nj
8 MHz ) n ) 12 ) 1
1
ƒ conv
OSC
n1 = 6 ; if ƒconv = 8 MHz
7 ; if ƒconv ≠ 8 MHz
n2 = 2 ; if tPVS = 0 µs
0 ; if tPVS ≠ 0 µs
NOTE: For continuous touch and D15−D14 = 00/10/11, the high duration of the PINTDAV signal is given by tPRE + tSNS with an oscillator clock of
8 MHz.
44
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
REG−00 of
PAGE−01
Is Updated
for
X Scan
Mode
Programmed
for Host
Controlled
Mode
Sample,Conversion &
Averaging for
X−Coordinate
Waiting for Host to Write
into REG−00 of PAGE−01
Detecting Touch
Reading
X−Data
Register
SS DEACTIVATED
Detecting
Touch
Waiting for Host to Write Into
REG−00 of PAGE−01
Touch Is Detected
PINTDAV
(As PENIRQ
[D15−D14 = 00])
PINTDAV
(As DATA_AVA
[D15−D14 = 01])
PINTDAV
(As PENIRQ & DATA_AVA
[D15−D14 = 10/11])
Touch Is Still There
The time needed to convert the Z coordinate under host control (not including the time needed to send the command over
the SPI bus) is given by:
t
coordinate
ȱǒtPVSǓȳ
ȧ125 nsȧ
Ȳ
ȴ
+
t
OSC
) 20
t
OSC
t
)2
OSC
) n2
NJ ƪǒ
N
AVG
t
N
BITS
Ǔ
)1
ƫ Nj
8 MHz ) n ) 12 ) 1
1
ƒ conv
OSC
n1 = 6 ; if ƒconv = 8 MHz
7 ; if ƒconv ≠ 8 MHz
n2 = 2 ; if tPVS = 0 µs
0 ; if tPVS ≠ 0 µs
NOTE: For continuous touch and D15−D14 = 00/10/11, the high duration of the PINTDAV signal is given by tPRE + tSNS with an oscillator clock of
8 MHz.
Programmed
for Host
Controlled
Mode
Detecting Touch
REG−00 of
PAGE−01
Is Updated
for
Z1−Z2 Scan
Mode
Waiting for Host to Write
into REG−00 of PAGE−01
SS DEACTIVATED
Sample,Conversion &
Averaging for
Z1−Coordinate & Z2−Coordinate
Reading Reading
Z1−Data Z2−Data
Register Register
Detecting
Touch
Waiting for Host to Write Into
REG−00 of PAGE−01
Touch Is Detected
PINTDAV
(As PENIRQ
[D15−D14 = 00])
PINTDAV
(As DATA_AVA
[D15−D14 = 01])
PINTDAV
(As PENIRQ & DATA_AVA
[D15−D14 = 10/11])
Touch Is Still There
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
REG−00 of
PAGE−01
Is Updated
for
X−Y Scan
Mode
Programmed
for Host
Controlled
Mode
Waiting for Host to
Detecting Touch Write into REG−00 of
PAGE−01
Reading
X−Data
Register
SS DEACTIVATED
Sample,Conversion &
Averaging for
Y−Coordinate
Sample,Conversion &
Averaging for
X−Coordinate
Detecting
Touch
Detecting
Touch
Reading
Y−Data
Register
Sample,Conversion &
Averaging for
Y−Coordinate
Touch Is Detected
PINTDAV
(As PENIRQ
[D15−D14 = 00])
Touch Is Detected
PINTDAV
(As DATA_AVA
[D15−D14 = 01])
PINTDAV
(As PENIRQ & DATA_AVA
[D15−D14 = 10/11])
Touch Is Detected
Non-Touch Screen Measurement Operation
The time needed to make temperature, auxiliary, or battery measurements is given by:
t+
NJ ƪǒ
N
AVG
N
BITS
Ǔ
)1
ƫ Nj
8 MHz ) n ) n ) 1
1
2
ƒ conv
t
OSC
) 15
t
OSC
) n3
t
OSC
where:
n1 = 6 ; if ƒconv = 8 MHz
7 ; if ƒconv ≠ 8 MHz
n2 = 24 ; if measurement is for TEMP1 case
12 ; if measurement is for other than TEMP1 case
n3 = 0 ; if external reference mode is selected
3 ; if tREF = 0 µs or reference is programmed for power up all the time.
1 + tREF /125 ns; if tREF ≠ 0 µs and reference needs to power down between conversions.
tREF is the reference power up delay time.
REG−00 of
PAGE−01
Is Updated
for
BAT1 Scan
Mode
Programmed for
Host Controlled
Mode With Invalid
A/D Function
Selected
Detecting Touch
Reading
BAT1−Data
Register
SS DEACTIVATED
Waiting for Host to Write Wait for Reference Power-Up Delay in Case
into REG−00 of PAGE−01
of Internal Ref Mode if Applicable
Sample,Conversion & Waiting for Host to
Averaging for
Write into REG−00
BAT1 input
of PAGE−01
PINTDAV
(As DATA_AVA
[D15−D14 = 01])
The time needed for continuous AUX conversion in scan mode is given by:
t+
NJ ƪǒ
N
AVG
N
BITS
Ǔ
)1
ƫ Nj
8 MHz ) n ) 12 ) 1
1
ƒ conv
where:
n1 = 6 ; if ƒconv = 8 MHz
7 ; if ƒconv ≠ 8 MHz
NOTE: The above equation is valid only from second conversion onwards.
46
t
OSC
)8
t
OSC
Detecting
Touch
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
REG−00 of
PAGE−01
Is Updated
for Continous
AUX SCAN
Mode
Programmed for
Host Controlled
Mode With Invalid
A/D Function
Selected
Waiting for Host to
Write into REG−00
of PAGE−01
Detecting Touch
Reading
AUX−Data
Register
SS DEACTIVATED
Wait for Reference Power-Up Delay in Case
of Internal Ref Mode if Applicable
Reading
AUX−Data
Register
Sample,Conversion & Sample,Conversion &
Averaging for
Averaging for
AUX input
AUX input
Sample,Conversion &
Averaging for
AUX input
PINTDAV
(As DATA_AVA
[D15−D14 = 01])
Port Scan Operation
The time needed to complete one set of port scan conversions is given by:
t+3
NJ ƪǒ
N
AVG
N
BITS
Ǔ
)1
ƫ Nj
8 MHz ) n ) 12 ) 1
1
ƒ conv
t
OSC
) 31
t
OSC
) n2
t
OSC
where:
n1 = 6 ; if ƒconv = 8 MHz
7 ; if ƒconv ≠ 8 MHz
n2 = 0 ; if external reference mode is selected
3 ; if tREF = 0 µs or reference is programmed for power up all the times.
1 + tREF /125 ns; if tREF ≠ 0 µs and reference needs to power down between conversions.
tREF is the reference power up delay time.
Programmed for
Host Controlled
Mode With Invalid
A/D Function
Selected
Detecting Touch
REG−00 of
PAGE−01
is updated
for
PORT SCAN
Mode
Waiting for Host to
Write into REG−00
of PAGE−01
Reading
BAT1−
Data
Register
SS DEACTIVATED
Wait for Reference Power-Up Delay in Case
of Internal Ref Mode if Applicable
Sample,Conversion &
Averaging for
BAT1 & BAT2 & AUX input
Reading
Reading
BAT2−
AUX−Data
Data
Register
Register
Waiting for Host to Write into REG−00
of PAGE−01
PINTDAV
(As DATA_AVA
[D15−D14 = 01])
47
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
DAC CHANNEL DIGITAL FILTER
DAC Channel Digital Filter Frequency Response
DAC Channel Digital Filter Pass-Band Frequency Response
48
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
DEFAULT BASS-BOOST FREQUENCY RESPONSE AT 48 ksps
DE-EMPHASIS FILTER FREQUENCY RESPONSE
De-Emphasis Filter Response at 32 ksps
49
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
De-Emphasis Error at 32 ksps
De-Emphasis Filter Frequency Response at 44.1 ksps
50
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
De-Emphasis Error at 44.1 ksps
De-Emphasis Frequency Response at 48 ksps
51
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SLAS379A− APRIL 2003 − REVISED JUNE 2004
De-Emphasis Error at 48 ksps
PLL PROGRAMMING
The on-chip PLL in the TSC2102 can be used to generate sampling clocks from a wide range of MCLK’s available in a
system. The PLL works by generating oversampled clocks with respect to Fsref (44.1 kHz or 48 kHz). Frequency division
generates all other internal clocks. The table below gives a sample programming for PLL registers for some standard
MCLKs when PLL is required. Whenever the MCLK is of the form of N*128*Fsref (N=2,3…), PLL is not required.
Fsref = 44.1 kHz
MCLK (MHz)
P
J
D
ACHIEVED FSREF
% ERROR
2.8224
1
32
0
44100.00
0.0000
5.6448
1
16
0
44100.00
0.0000
12
1
7
5264
44100.00
0.0000
13
1
6
9474
44099.71
0.0007
0.0000
16
1
5
6448
44100.00
19.2
1
4
7040
44100.00
0.0000
19.68
1
4
5893
44100.30
−0.0007
48
4
7
5264
44100.00
0.0000
Fsref = 48 kHz
52
MCLK (MHz)
P
J
D
ACHIEVED FSREF
% ERROR
2.048
1
48
0
48000.00
0.0000
3.072
1
32
0
48000.00
0.0000
4.096
1
24
0
48000.00
0.0000
6.144
1
16
0
48000.00
0.0000
8.192
1
12
0
48000.00
0.0000
12
1
8
1920
48000.00
0.0000
13
1
7
5618
47999.71
0.0006
16
1
6
1440
48000.00
0.0000
19.2
1
5
1200
48000.00
0.0000
19.68
1
4
9951
47999.79
0.0004
48
4
8
1920
48000.00
0.0000
MECHANICAL DATA
MTSS002C – JANUARY 1995 – REVISED DECEMBER 1998
DA (R-PDSO-G**)
PLASTIC SMALL-OUTLINE
38 PINS SHOWN
0,30
0,19
0,65
38
0,13 M
20
6,20
NOM
8,40
7,80
0,15 NOM
Gage Plane
1
19
0,25
A
0°– 8°
0,75
0,50
Seating Plane
0,15
0,05
1,20 MAX
PINS **
0,10
30
32
38
A MAX
11,10
11,10
12,60
A MIN
10,90
10,90
12,40
DIM
4040066 / D 11/98
NOTES: A.
B.
C.
D.
All linear dimensions are in millimeters.
This drawing is subject to change without notice.
Body dimensions do not include mold flash or protrusion.
Falls within JEDEC MO-153
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